What is the complete back-and-forth motion of an object called?

Current 1 of 8.4 a runs for 240 seconds and then stops. current 2 is 10.5 a. how long does current 2 have to un to deliver the same amount of charge as current 1? 88.28 192 s 2016 s 21,000 s

The density of a liquid could be found by using

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.